Zerker TomeFollow

Okay, so I'm d*cking around a bit today on my zerker. Couldn't find a group in PC so I decide to head to Halas to train up. Do my thing there then head to PoK to paruse the tomes. Lo and behold, there is a tome my 24 zerk can use called Derisive Strike. I was like WOOT! I buy it, take it to the nearest GM and train. I go to some rinky dink area and try it out. Next thing I know I'm more confused than hell. Can someone help me out?

The tome reads something like "Aims a blunt axe at your opponents vitals causing them to bleed for a short time" (Sounds like a DoT to me)

In gameplay, it reads "A giant rat looks confused" K...I would think that sounds like a lull. However everything attacks.


So WTF? It's not a DoT, and it's not a Lull. Can someone help me figure this out?